From the Departments of Neurology and Ophthalmology (Dr Pearce) and Osteopathic Manipulative Medicine (Drs Zatkin and Bruner) at the Michigan State University College of Osteopathic Medicine in East Lansing.

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Context:
Musculoskeletal disorders are a common problem among ophthalmologists, likely due to ergonomic challenges. Most research on the topic has been survey-based studies, which carry inherent weaknesses.

Objective:
To examine the frequency and pattern of musculoskeletal dysfunction induced by performing a surgical procedure and to quantify the improvement after ergonomic interventions.

Methods:
Ophthalmology residents from a single academic institution were invited to participate in the study on a volunteer basis. Preexisting musculoskeletal disorders; previous spinal, cervical, or shoulder surgery; or limited range of motion of the upper body or arms were exclusion criteria. The interventions consisted of a surgical simulation session and a control session, each lasting 2 hours. For the surgical simulation session, a musculoskeletal examination was performed at the beginning and end of the 2-hour session after the participants used the Eyesi Cataract Surgery Simulator (VRmagic). A musculoskeletal examination was performed by the palpatory screener (M.A.Z.) at the beginning and conclusion of the 2-hour control session, which consisted of both passive and active tasks. The musculoskeletal screener was blinded as to which session the participant was completing at the time of the examinations, as well as any musculoskeletal examination findings from before the intervention. All participants completed both sessions, but they were randomized into which session they were to complete first. Participants completed each session one after the other.

Results:
Eight participants completed both sessions, and 32 musculoskeletal examinations were performed. In the surgical simulation session, after using the simulator, 5 of 8 participants had an increase in the number of spinal levels with tissue texture abnormalities, and 3 had no change. Of those in the control session, 5 participants had a decrease in the number of spinal levels with tissue texture abnormalities after a period of rest. Three participants in the control session had an increase in the number of affected spinal levels. The mean (SD) change in number of affected spinal levels in the surgical simulation session and control session was 1.3 (1.2) and −0.6 (2.0), respectively (P=.125). Age, sex, level of training, baseline somatic dysfunction, and which session was completed first did not affect results.

Conclusion:
The majority of participants in the surgical simulation session had an increase in degree of somatic dysfunction, whereas the majority in the control session had a decrease in degree of somatic dysfunction. Although the sample size of this pilot study was too small to show statistical significance, a trend was observed, and further study is warranted.

Low back pain costs billions of dollars annually in the United States and is the most common cause of work-related disability, according to the National Institutes of Health.1,2 Health care practitioners are not immune to occupational injuries and illnesses. A survey-based study of 77 surgeons reported that up to 80% have had pain while operating, and 43% have had to take breaks while performing a surgical procedure to rest.3 In 1994, a survey-based study of ophthalmologists showed that 54% of those surveyed had episodes of back pain.4 In 2005, another survey of ophthalmologists revealed that 52% had symptomatic musculoskeletal disorders, 15% of whom had to limit their work as a result of the pain.5 In 2011, 72.5% of a surveyed sample of oculoplastic surgeons reported they had pain while operating, and nearly 10% stopped operating because of pain or spinal injury.6

In 2012, the American Academy of Ophthalmology joined 6 ophthalmologists with a group of ergonomics specialists to create a task force to investigate work-related musculoskeletal disorders in ophthalmologists.7 The goals of the commission were to investigate trends in occupational musculoskeletal disorders, educate practitioners and the ophthalmic surgical equipment industry to create programs for the prevention of work-related injuries, and establish guidelines for ophthalmic equipment to decrease the incidence of musculoskeletal disorders in ophthalmologists.7 The task force, the National Institute of Occupational Safety and Health, and other researchers have identified several risk factors ophthalmologists face that predispose them to musculoskeletal stress. These factors include static loads, awkward and nonneutral postures while working, large patient volumes, high cognitive load and mental stress, and limited adjustability of clinical and surgical equipment.3,6-9 During microsurgical ophthalmic procedures, prolonged static positioning with cervical extension and unsupported arms results in excessive workload in the cervicobrachial region, which may accelerate disk degeneration.8

With the repetitive tasks, awkward positions, and frequent bending and twisting required in ophthalmology, physicians are at risk for work-related somatic dysfunction. The Glossary of Osteopathic Terminology9 defines somatic dysfunction as “impaired or altered function of the related components of the somatic (body framework) system, skeletal, arthrodial and myofascial structures, and their related vascular, lymphatic, and neural elements.” Pain is usually the first symptom, but patients may also have loss of function, decreased range of motion, numbness, tingling, swelling, redness, spasms, or weakness.10

Tissue texture abnormality (TTA) is a descriptor of the presence of somatic dysfunction. Palpation allows for the detection of TTA and is classically described as the subjective assessment of tissue texture change (eg, tension, edema, hypertrophy, atrophy), asymmetry, restricted motion, and tenderness.11 Skills in palpation, though inherently subjective, allow for the ability to detect changes in palpatory findings at affected spinal levels.11 By assessing each spinal level for the presence of TTAs, the overall presence of somatic dysfunction can be quantified by the sum of the total affected spinal levels.

Survey-based studies on work-related musculoskeletal disorders in physicians have inherent weaknesses. These studies can have low response rates and gather little additional information aside from what is being investigated. Additionally, cross-sectional surveys of this nature cannot establish causality but can merely identify associations. Thus, there is a need to develop a model to quantify the degree of musculoskeletal somatic dysfunction induced by particular activities. This model could allow for the objective measurement of the effectiveness of interventions, such as increased ergonomics, behavioral changes, and equipment modifications. The purpose of the current pilot study was to quantify the amount of somatic dysfunction induced by performing ophthalmic microsurgery using a blinded, controlled study model.

Methods

Approval was obtained by the local institutional review board, and the study protocol adhered to the Declaration of Helsinki. Ophthalmology residents from a single academic institution were invited to participate in the study. Residents were excluded if they had preexisting musculoskeletal disorders; previous spinal, cervical, or shoulder surgery; or self-reported limited range of motion of their upper body or arms. Participants completed both the surgical simulation session and the control session and were randomly assigned into which session they would complete first. Both sessions were to be completed in succession. The musculoskeletal examinations in each session were performed by the same physician (M.A.Z.), who completed a residency in neuromusculoskeletal medicine and osteopathic manipulative medicine.

Before the 2-hour surgical simulation session, participants underwent a musculoskeletal examination performed by the palpatory screener (M.A.Z.). Then they spent 2 uninterrupted hours performing tasks on the Eyesi Cataract Surgery Simulator (VRmagic) without standing up at any time. The tasks completed on the surgical simulator were left to the discretion of the participant. The posture of the participants was not corrected at any time. On completion of the 2-hour session, a follow-up musculoskeletal examination was performed.

Before the control session, a musculoskeletal examination was performed by the same palpatory screener as in the surgical simulation session. The participant then spent 28 minutes performing a passive activity of his or her choice, such as reading, using the computer, watching videos, listening to music, or sleeping. After the passive activity, a 2-minute active break was taken, during which time the participants could either stand and stretch or walk around. Passive activities and active breaks were repeated every 30 minutes until the 2-hour session was over, at which time another musculoskeletal examination was performed.

During the musculoskeletal examinations, participants were asked to lay prone on an examination table, and the screener used 1 or both hands to lightly palpate along the participant's spine, just lateral to the spinous process in the medial groove, looking for TTA. Tissue texture abnormality was defined as the subjective presence of edema, hypertrophy, atrophy, rigidity, bogginess, asymmetry, restricted motion, or tenderness. The presence or absence of TTA was recorded on a data sheet at each spinal level from the occipitoatlantal joint (C0) to the sacral base (S1). Neither the severity of the TTA nor the laterality was documented because a more severely affected spinal level would likely have some effect on the adjacent levels. When a data sheet was completed, the screener was not allowed to reference a previous examination. No osteopathic manipulative treatment techniques were initiated.

A paired t test was used to determine the average change in the number of affected spinal levels in the surgical simulation session. Statistical significance was defined as P<.05.

Results

A total of 32 musculoskeletal screening examinations were performed on the 8 participants. Five participants were men and 3 were women. The mean age of participants was 30.6 years, with a range of 27 to 36 years. Three first-year ophthalmology residents (PGY-2), 1 second-year ophthalmology resident (PGY-3), and 4 third-year ophthalmology residents (PGY-4) participated. Standing and stretching were performed in 17 of the active breaks, and walking was performed during 14.

The results from the musculoskeletal examinations are summarized in the Figure. In the surgical simulation session (Figure A), 5 participants had an increase in the number of spinal levels with TTAs, and 3 participants had no change after using the simulator. During the control session (Figure B), 5 participants had a decrease in the number of spinal levels with TTAs after a period of rest, and 3 had an increase in the number of affected spinal levels. The mean (SD) change in the number of affected spinal levels in the surgical simulation session and control session were 1.3 (1.2) and −0.6 (2.0), respectively (P=.125). Age, sex, level of training, baseline somatic dysfunction, and which session was completed first did not affect results. Additionally, data were further analyzed in anatomic subgroups (C0-C7, T1-T4, T5-T9, T10-T12, L1-L2, and L3-S1), but results were not significant.

Figure.

Results of the musculoskeletal examinations completed in (A) the surgical simulation session and (B) the control session.

After the surgical simulation session, the majority of participants had an increase in the number of spinal levels with TTAs, and the majority of the participants in the control session had a decrease in the number of affected spinal levels after a period of rest. An unexpected result was the percentage of participants in the control session who had an increase in the number of affected spinal levels. This result could be explained by the type of activity chosen during the period of rest. During the control session, an attempt was made to neutralize any preexisting musculoskeletal disorders by incorporating a combination of activities (both passive and active). The passive activity portion of this session was left to the discretion of the participant and was not documented. It is possible that the activity chosen was not as neutral as intended and could account for some increase in musculoskeletal dysfunction.

A number of strengths are present in the design of this pilot study. The study was quantifiable and it allows comparison with future studies. The musculoskeletal screener (M.A.Z.) was blinded as to which session the participant was completing at the time of the examinations, as well as to any musculoskeletal examination findings from before the intervention. Although some other studies attempted to use family practitioners as a control group for studying ophthalmologists,3 the present study attempted to isolate, study, and control for the task in a single population (ie, ophthalmic surgeons). Another inherent strength of the study design is the use of a single palpatory examiner so as to eliminate interobserver variability.

Several limitations are also present. This study had a small number of participants. Although results were not statistically significant, a trend was noted and deserves a larger, more definitive study. Also, although interobserver variability was eliminated, having multiple palpatory examiners could potentially strengthen the data by showing consistency of trends among different examiners. The unexpected result of the control session raises questions about whether the activities chosen did not adequately achieve the goal of neutralization of musculoskeletal dysfunction. These questions could be addressed in future studies by having participants lie supine for the passive activity. Another area of subjectivity and potential weakness of the study relates to the study participants themselves, because voluntary or involuntary muscle contraction by the subjects at the time of the musculoskeletal examination could have been misinterpreted as somatic dysfunction.

The primary outcomes of this pilot study raise additional questions that would be interesting to examine. Future studies could examine surgeons in training compared with more experienced surgeons, or the role that specific muscle groups may play. Because the affected spinal level in this study could mean many different things (eg, tenderness, decreased range of motion), future studies could further characterize those dysfunctions.

Although our study measured the acute changes associated with a particular activity, chronic musculoskeletal dysfunction is often the result of persistent overuse and repetitive injuries. The incidence of back pain among surgeons, specifically ophthalmologists, has been explored and, if related to musculoskeletal dysfunction, is a potentially preventable problem. However, back pain can be the result of factors independent of musculoskeletal dysfunction, but investigating other factors was beyond the scope of this study. Regardless, the potential musculoskeletal trauma induced by repetitive stress has serious implications, and this study lays the groundwork for future research.

Conclusion

The purpose of this pilot study was to develop a prospective, blinded, controlled, quantifiable assessment of acute musculoskeletal dysfunction in ophthalmologists. In this study, the majority of participants showed an increase in the number of TTAs after performing tasks on a surgical simulator and a decrease in the number of TTAs after rest. Although the sample size was too small to demonstrate statistical significance, a trend was observed, and further study is warranted. Similarly designed studies may be applied to a number of scenarios to evaluate work-related musculoskeletal stress. These results lay the groundwork for additional research to quantify the effectiveness of ergonomic and behavioral interventions, such as muscle stretching and strengthening programs. Hopefully, through continued evidence-based research and innovation, we can continue to advance our knowledge of work-related musculoskeletal disorders in ophthalmologists, as well as other specialty-specific ergonomic hazards, and move toward prevention.

Author Contributions

All authors provided substantial contributions to conception and design, acquisition of data, or analysis and interpretation of data; all authors drafted the article or revised it critically for important intellectual content; all authors gave final approval of the version of the article to be published; and all authors agree to be accountable for all aspects of the work in ensuring that questions related to the accuracy or integrity of any part of the work are appropriately investigated and resolved.